This invention relates generally to programmable analog and digital circuit arrays and, in particular, to methods and apparatus for configuring such circuits arrays.
In the past decade data processor clock speeds have increase from 10 MHz to 100 MHz and beyond. It is conceivable that processor clock speeds will increase by the same amount over the next decade, perhaps attaining speeds as high as 2,000 MHz. With these advances, digital signal processing will replace many current applications that today utilize analog circuits to condition and manipulate analog signals.
This is a desirable development, in that analog circuits typically require zeroing for accuracy as they tend to drift with age and environment. Analog circuits are also susceptible to noise. Furthermore, most analog circuits are not very xe2x80x9cchangeablexe2x80x9d after they are constructed; whereas a digital processor device can be reprogrammed after construction. Although digital processors can be reprogrammed, they are still limited in the way they are interconnected to other devices.
Furthermore, some currently available programmable analog circuit arrays provide a computer program and method for specifying the interconnections between analog circuit modules or functions. Once interconnected in the desired configuration and subsequently tested and qualified, some hundreds or thousands of identically constructed analog arrays can be produced, either by programming other programmable arrays or by mask programming arrays at manufacture.
Reference in this regard can be had, by example, to a publication entitled xe2x80x9cElectrically Programmable Analog Circuit Design Handbookxe2x80x9d, IMP, Inc., 1996, for a description of one type of programmable analog circuit array and to a software development system for same (Chapter 2).
As can be appreciated, it would be desirable to provide a mechanism to convert or migrate such a design into the digital domain. At present, such a mechanism is not known to exist.
It is a first object of this invention to provide an improved analog and digital integrated circuit architecture that overcomes the foregoing and other problems.
It is a second object of this invention to provide methods and apparatus to convert a programmable analog array specification into a program executable by one or more digital signal processors, so as to perform the identical or substantially identical function or functions as the analog array.
In accordance with an aspect of this invention, the inventors have eliminated the interconnectivity drawback by incorporating a plurality of digital processors and support devices onto a single substrate. The digital processors and support devices are programmably interconnected to achieve a desired architecture. These programmably interconnected programmable (PIP) devices may be considered as xe2x80x9cliquidxe2x80x9d circuits, and are used to create a Programmable Signal Processing Array (PSPA). The concept is similar in some respects to field programmable gate array (FPGA) devices, except that the logic elements of the FPGA are replaced with entire processors that can be individually programmed to perform desired analog and digital functions.
In accordance with this invention, a substrate comprises a plurality of digital data processors, such as digital signal processors and/or RISC processors, and related support devices, including analog circuit blocks if desired, that can be programmably interconnected together.
Also disclosed are methods and apparatus to convert a programmable analog array specification into a program executable by one or more digital signal processors, such as those found in the aforementioned PSPA device, so as to perform the identical or substantially identical function or functions as the programmed analog array.